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Technical Topics => Equipment => Topic started by: ChrisSmolinski on October 31, 2019, 1207 UTC

Title: 950 foot LoG (Loop on Ground) Antenna
Post by: ChrisSmolinski on October 31, 2019, 1207 UTC

Not sure I've posted anything detailed about this antenna, so here goes...

I upgraded the 350 ft LoG to 950 ft earlier this year.  The previous LoG was made of #16 insulated wire. The New 950 ft LoG is made from unshielded ethernet cable, as it turned out to be a fairly inexpensive choice for such a long run, I bought a 1000 ft spool for about $35 shipped. All 8 wires are used in parallel, they are shorted on each end of the run at the feedpoint, which is one of my 450 ohm Cyclops transformers with an F connector: https://www.blackcatsystems.com/rf-products/cyclops_rf_ham_shortwave_radio_matching_transformer.html

The ethernet cable is laid around the perimeter of much of the yard at ground level, and crosses through an uncleared wooded area. It also crosses the driveway (I will need to deal with this once we enter winter snow blowing season). This placement avoids issues with the lawn mower. The coax output of the Cyclops transformer then runs underground through one of my coax conduits and up to the shack.

Performance on LW and MW is excellent as expected, signal levels of many stations are stronger vs the sky loop. It generally gives me a different mix of DX stations vs the 670 ft sky loop antenna.  It deteriorates as you go up in frequency as expected, at say CHU 3330 it seems comparable to the sky loop, but by 4 MHz the sky loop is starting to win. RFI pickup seems to be about the same as the sky loop, better in some areas, worse in others.

Based on my previous experiments with smaller LoG antennas performance scales with frequency, smaller runs are better at higher frequencies. But traditional antennas win there in my experience, so a smaller LoG isn't useful for me, but could be for those without the space or XYL/HOA permission for traditional antennas.

Title: Re: 950 foot LoG (Loop on Ground) Antenna
Post by: flexoman61 on October 31, 2019, 1308 UTC

Sounds good Chris, I've been needing a better antenna for LW and MW.

Do you think snow and ice cover will affect a LoG antenna or burying a few short 10 foot sections?

Thanks!

Title: Re: 950 foot LoG (Loop on Ground) Antenna
Post by: ChrisSmolinski on October 31, 2019, 1330 UTC

Last winter the 350 ft LoG worked OK under 3.5" of snow. I'll have to see how this one does under deeper snow: https://www.hfunderground.com/board/index.php/topic,50567.0.html

It's a really great antenna for LW/MW, and now is a good time to put one up, err down, since lawn care season is winding down.